1. Field of the Invention
The invention relates to a paper shredding roller for a paper shredder and to the method for manufacturing the same, more particularly to an improved paper shredding roller which is capable of cutting paper documents into smaller pieces than the prior art.
2. Description of the Related Art
Paper shredders are used to replace tearing or burning of confidential documents when destroying the latter. Referring to FIG. 1, a conventional paper shredder for cutting paper documents into strips is shown to comprise a pair of shredding rollers (A) which respectively include a plurality of flat circular knives that are separated by circular spacers. The cutting edge of the circular knives may be plain or saw-toothed. A main drawback of the conventional paper shredder shown in FIG. 1 is that the size of the strips produced thereby is relatively large, thus making it possible to piece together the shredded documents. Furthermore, since the strips are not compact, the enclosure (not shown) for receiving the strips is easily filled.
FIG. 2 is an illustration of another conventional paper shredder. The paper shredder comprises a pair of shredding rollers (B) which rotate synchronously in opposite directions and which respectively include a plurality of spaced circular knives (B1). The periphery of each of the circular knives (B1) is formed with a predetermined number of equiangularly spaced ratchet teeth-type cutting elements (B11). The cutting elements (B11) of the circular knives (B1) are aligned, thereby forming a number of axially extending rows of cutting elements (B11) along the length of a rotatable knife shaft (B2). The paper shredder shown in FIG. 2 can cut paper documents into smaller bits and pieces, thereby overcoming the drawbacks of the paper shredder shown in FIG. 1. However, since contact between the cutting elements (B11) of the circular knives (B1) of the shredding rollers (B) occurs when the paper shredder is in operation, resistance to movement of the shredding rollers (B) is produced. Thus, a motor with a greater output power is required in order to overcome the resistance that is generated, thereby resulting in higher costs.
Still another example of a conventional paper shredder has a pair of shredding rollers that are formed as cylindrical shafts with a plurality of staggered cutting teeth provided thereon. Contact between the cutting teeth of the shredding rollers does not occur when the paper shredder is in use, thereby overcoming the drawbacks associated with the paper shredder shown in FIG. 2. However, a computer numeric controlled (CNC) process is employed so as to form the cutting teeth on the shredding rollers. The shredding rollers are thus expensive and inconvenient to manufacture.